How bout you??? According to physics traction is not dependent on surface area. I'm vehicles with extremely tall wheels that absorb energy from impact run more efficiently do to lower rotating weight and driven by direct hub drive dc motors powered by small diesel generator/ solar and battery reserve. What would this look like? Who cares about looks!
That's according to classical physics. You'll notice that race cars from the 60's and earlier had skinny tires because of the principle that the friction coefficient was not dependent on surface area but since then, race car tires have gotten wider and softer. At first the mechanism as to why wider tires worked better wasn't known but in the 80's they realized that it had to do with the structure of materials at a microscopic level. Basically the surfaces are not smooth at a microscopic scale and hence are not in continuous contact though pressure increases the percentage of the surfaces that actually interact more so than the overall cross sectional surface area hence the independence on surface area was actually an illusion and could be greatly affected by the type of material involved hence soft tires designed to adhere, actually bonding to the road surface. Physics is a lot like statistics, unless you consider every possible consideration and there's likely an infinite number of considerations, the conclusions drawn are not necessarily conclusive. Hub motors actually increase the rotational and unsprung mass considerably creating handling problems and additional energy loss due to the suspension. There's already diesel serial hybrid buses that use hub motors but at those scale, the additional rotational and unsprung mass is a much smaller percentage of the overall vehicle mass.
Who said traction was not dependent on surface area? Tires of the same compound the wider on will have more traction, the only wat out isis a different better compound. If the tire has less weight in a taller configuration it will have more centrifugal energy.
John W has is, the effect is called sticktion. And as for hub motors being heavy. you could use hydraulic drive.Hydraulic motors are about tenth the size of combustion engines for the same power. Given that the required pump and motors would weigh about the same as a gearbox and would also do that job, its a possibility.
I haven't been in a physics class for 20 years, so don't know what those guys are talking about. I do know race cars need more traction than normal vehicles because of the maneuvering they do at high speeds, plus an engine many times more powerful than anything we would likely need. I think of road bike and mountain bike tires; the first is so much easier to propel than the latter, but isn't very good in the mud. Most vehicles don't need wide tires, but they are a macho factor.
good idea, I've been wondering about that. It will actually be better in snow, as the smaller contact patch will cause the tire to sink through the snow to contact the paving underneath. If you need proof, compare a large heavy car with a light compact. Weight difference is 3 to 1, yet, the tires are about the same width. The heavier car is much better in the snow for the above reason. The thick tires on the light car are only for style. But style has everything to do with tires. Look at the extremely high aspect ration tires (or is it low, anyway the ones only an inch or two between paving and rim). They are expensive, very fragile, damaged by small potholes. Yet they are becoming standard equipment in many brands, ie, you can't get the car without these impractical tires. .
